What does melancholy mean? (I'm addicted to "Suzumiya Haruhi no chokuretsu" or "the Melancholy of haruhi Suzumiya") I looked on google, ask, etc but it says "depressed", but she's not sad in the anime/manga... So is this the only description of the word?
Melancholy can mean several things, not just depressing. It can mean serious, sad, gloomy, emotionless etc. It can also mean black bile. It can be used as a synonym for pensive too. As for it being in the title, just because it's in the title doesn't necessarily mean that the person would be melancholy. You're taking the title too literally.
ahhh you my friend should have posted this somewhere else anyway in the anime (since that's where you got it from), she is indeed melancholic, the series gets its title close to the end of the series when Haruhi starts to think that Kyon doesn't understands her anymore, thus making her "sad" since she thought he was the one that would believe in her no matter what, but seeing that Kyon is just a normal human, anyone would reach their limit after a while so melancholy means, like you said depressed, sad, etc.
melancholy: a feeling of thoughtful sadness a constitutional tendency to be gloomy and depressed characterized by or causing or expressing sadness; "growing more melancholy every hour"; "her melancholic smile"; "we acquainted him with the ... Black Bile (since it was mentioned): a humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy Melancholy is that state of alienation or weakness of mind which renders people incapable of enjoying the pleasures, or performing the duties of life. It is a degree of insanity, and often terminates in absolute madness. There are other terms for it as well, depends on the context.
This is also presuming that the original japanese word doesn't have alternate translations aside from 'melancholy'. Translators from .jp to english tend to take many, many artistic liberties to make things sound better in english. I couldn't say what else it could have been (if anythign at all) because pretty much 80% of what I do know (believe me it's not a lot either) has been gleaned from anime and video games. And it also assumes the title has anything to do with the show. Which is not exactly a pre-requisite. All that said I am inclined to agree with crazytuna, in that it would be a reference to how upset/sad she [suzumiya] got around the conclusion of the series.